Case unstacking machine



4 Sheets-Sheet 1 Filed Nov. 29, 1962 Feb. 16, 1965 M. c. KLOTZ 5 5 CASE UNSTACKING MACHINE Filed Nov. 29, 1962 4 Sheets-Sheet 2 Feb. 16, 1965 MC. KLOTZ CASE UNSTACKING MACHINE 4 Sheets-Sheet 3 Filed Nov. 29, 1962 l ll llllllll-llllllnl Q. m w.

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ig/J Feb. 16, 1965 M. c. KLOTZ CASE UNSTACKING MACHINE 4 Sheets-Sheet 4 Filed Nov. 29, 1962 1395320150 [bk :0 /lizz. %zmc% United States Patent 3,169,661 CASE UNSTACKING MACHINE Milton C. Klotz, Chicago, 11]., assignor to Warren Du Brolf Filed Nov. 29, 1962, Ser. No. 241,010 5 Claims. (Cl. 221-210) This invention relates to a case unstacking machine, and, more particularly, to a machine equipped with improved single case ejector means for increasing the speed It is a general object of this invention to provide novel' ejection means for use in an unstacking mechanism whereby cases are rapidly and smoothly removed from themechanism to permit faster operation of the unstacker. The basic machine with which the'in vention is concerned involves a continuously-operating conveyor which advances stacks of cases into a frame. The frame lifts all but the lowest case by grasping and elevating the secondfrom-the-bottom case-whereupon the conveyor is able to remove the bottom case. Thereafter, the procedure is repeated within the frame until all of the cases in the stack have exited singly from the frame.

Another object of the invention is to provide novel ejection means in conjunction with an unstacker utilizing a horizontally-traveling conveyor and wherein there is a certain slippage between the cases or cartons supported on the conveyor and the conveyor itself, the ejector compensating for this slippage.

Still another object of the invention is to provide a novel case ejector for a case unstacker wherein the apparatus is characterized by rugged and simple mechan-.

ical interconnection to cause positive action of the ejector and at the same time facilitate repair thereof by making any inoperative portions readily accessible. In this con nection, it will be appreciated that unstacking mechanisms of the character with which the invention is concerned are used in areas not serviced by skilled mechanics dairies, bottling plants, etc. Most often, the unstacking mechanisms are in or immediately adjacent a warehouse, where stacks of cartons are stored on pallets and are unstacked for delivery on a conveyor to the place offilling. Such a warehouse area may be essentially remote from a place where intricate repairs can be performed,

, 13 designates generally a stack of cases carried by the 3,169,661 Patented Feb. 16, 1965 FIG. 8 is a fragmentary perspective view of the mechanism seen in FIG. 7.

Referring to the drawing, the numeral 10 designates generally a frame supported on a floor 11 which also supports a chain conveyor 12, the conveyor 12 having spaced-apart chain strands 12a. In FIG. 1, the numeral conveyor 12. The conveyor 12 is seen to pass through the unstacking mechanism frame 10, the leaving end of the conveyor 12 supporting a single'ca se 14. For the purpose of breaking down the stack 13 into itsindividual cases 13a, 13b and 13c (see FIG. 1), the frame 10 is equipped with a vertically movable carriage generally designated 15 and which carries pressure pads 16 and 17 (see FIG. 6). The pad 16 (see FIG. 5) is seen to be mounded' for horizontal movement relative to the pad 17 and is equipped with an air cylinder 18 so that the pad 16 maybe moved toward the pad 17 to grasp the case 1312 and elevate cases 13b and 13c relative to the case 13kz-thus permitting the case 13a to be re-' movedfrom the frame 10, i.e., follow the course of the case 14. i

As mentioned previously, the instant invention is concerned with an ejection mechanism, and this mechanism is advantageously employed with the Hageline construction seen in Patent 2,995,273. Hence, reference may be made'to that patent for additional details of operation and construction of features not particularly concerned with the ejector. In line with that, it is merely pointed out that the carriage 15 is connected to abell crank 19,

' powered by'a motor 20, a drive shaft 21 being interposed between the crank 19 and the motor 20 (see FIGS. 1 and and also the mechanisms are subject to rough treatment and wear, usually through unskilled labor. 7 Hence, ruggedness and simplicity of operation are prerequisites.

Other objects and advantages of the invention may be seen in the details of construction and operation set down in' this specification. 7 The invention is described in conjunction with an illustrative embodiment in the accompanying drawing, in which a r FIG. 1 is a fragmentary elevational view, partially broken away, of a case unstacker embodying the inventive teachings; I V

FIG. 2 is an interior fragmentary elevational view showing details of one of the carton-lifting elements;

FIG. 3 is an enlarged fragmentary elevational view of the central portion of FIG. 1;

FIG. 4 is an enlarged end elevational view partially in section, of the apparatus seen in FIG. 1;

FIG. 5 is a plan elevational view, partially in section, to feature the lower portion of the apparatus seen in FIGS. 1 and 4; a

FIG. 6 is an end elevational view, in fragmentary form, and of the opposite end to that shown in FIG. 4; a

FIG. 7 is an enlarged fragmentary view, partially in In the operation of the unstacking machine, a stack of cases engages a trip plate 22 (see FIG. 4) which is pivotally mounted on the flame 10 and energizes the motor 20 to elevate the carriage 15. The carriage 15 is guided by posts 23 and 24' (see FIG. 1) and adjacent the upper limit of its travel engages a limit switch, (not shown) for. actuating the air cylinder- 18 to grip the second-from-thebottom case 13b and thereafter slightly elevate thecases 13b and 13c to release the case 13a. For the purpose of rapidly ejecting the case 13a from a position of alignment with the pads 16 and.17, a pusher element 25 is provided (see FIG. 8) which is seen to be essentially fan-shaped and which is pivotally mounted as rods 28.

Therods 28 are also rigidly interconnected to a second crossbar 29 which is equipped with a slide 30 adapted to move within the slot 31 provided in the main framev 10 (see the bottom of'FIG. 4). Thus, as'the crossbar 29 is moved in the-directionof conveyor movement, it is operative to move the pusher element 25 accordingly to rapidly eject a case from the positionof alignment with pads 16 and 17. The pusher element 25 is pivotable to the dotted line position 25a in FIG. 7 so as to pass back under the next bottommost case, i.e., 13b inthe illustration given. I

' The means for moving crossbar 29 includes rollers 32 'rotatablymounted on the curved end portions 29a of the crossbar 29 (see FIG. 8). The rollers 32 operate within elongated grooves 33 provided on the inside faces of the actuatora'rms generally designated 34. The arms '34 arepivotally mounted on the frame 10 as at 35 (see FIG. 3) and in swinging forwardly between the positions the upward movement of the carriage 15, which is' equipped with rollers 36 operating against the posts 24 V and 4). As can be appreciated from a consideration of FIG. 1, as the carriage 15 rises, the cam roller 41 rises with it from the lowermost posit ion designated-11a to an upper position 411), and'during the initial portion of the travel is in the vertical legZa of the 'L-shaped slot 42.

At about ten oclock of the travel of crank 19, the cam roller 41 reaches the cam portion 42b (see FIG. 3) of the slot 42 and in traveling further upwardly, causes the arms 34 to pivot from the 34a to the 34b position in FIG. 1.

a 4 ment, the air cylinder 18 onthe clamping member 16 is energized through an air line 18a to move piston 18]) against spring 180 and the clamping elements or pads 16 and i7 grip the case 13bto elevate it slightly and thereby permit a case 13a to be carried out of the frame it) by the continually moving strands 12a.

During the same upward movement of the carriage 15, the roller 41 is moved upwardly in the slot 42 until This is attended by the longitudinal movement of the pusher element 25, which is rigidly tied through the rods 28 to the crossbar 29. The pivotal movement of the arms 34 is guided by means of rollers 43 operating against the insides of the frame 10 as at 10a in the lower lefthand corner of FIG. 4.

Summarizing this operation, each time the carriage 15 goes up, the cam rollers 41 on the lower ends of the arms 39 cause the pivot arms 34 to move forwardly and upwardly through about a 30 are, causing the slide arrangement, including the crossbar 29 and the pusher element 25, to move forward and pull the pusher element 25 to eject the case 13a. a

The return movement of the pusher 25 is provided by the downward movement of the carriage l 'through' the inter-engagement of the cam roller 41 with the walls of the L-shapedslot 42.

The completion of the downward movement of the carriage 15 is attended by retraction of the pad 16 to deposit the case 1312 on the conveyor in the position recently vacated by the case 13a.

To protect the pusher slide mechanism, including the elements 25, 28 and 29, from being slammed back into starting position, the rods 23 are connected at their fortheir forward ends by means of spring 4 8. Intermediate the ends, the bars 46 are slotted as at 49 for the receipt of posts 5 also upstanding from the frame It). The' brake bars 46 are seen to be aligned vertically with the chains 12a constituting the conveyor 12. Thus, as the pusher mechanism, including elements 25, 28 anda29, is returned to starting position by the downward movement of the carriage ,15, the bars 46 are urged apart slightly but still exert a frictional retarding action on the rollers 45.

As the next cycle is commenced and the pusher 25 is advanced, a yielding engagement is achieved through the operation of the springs 51'whieh are interposed between the crossbars 27 and 44.

Operation 7 In achieving the objective of providing a simple, rugged, mechanical feature for rapid ejection of cases from an unstacker, the arms 34 and the associated components eliminate the need for any complex electrical or pneumatic controls. Stacks of cases as at 13a, 13b and 130 in FIG. 1 move along'the twin strands 12a of, the conveyor 12 until the second-from-the-bottom case 13b engages the actuating plate 22 (see 'FIG. 4). Inasmuch as'there is slippage between'the bottom case 13:: and the conveyor strands 12a, this'stabilizes the stack within the frame V and in alignment withthe pad elements 16 and 17. The depression :of the plate 22 actuates the motor 20 and through the bell crank '19 raises the carriage, the carriage being guided by the posts 23 and24.

Shortly before the top of the bell crank cycle of movean angled projection 42b is reached. The continued upward movement of the roller 41 then necessarily pivots the arms 34 to the 34b position seen in FIG. 1. Each arm 34 has a second slot 33 (in the illustration given, on the inwardly-facing side) so that the arms 34 in cross section have the shape of an H. Riding in the inwardlyfacing slot is a roller 32 provided on a rigid crossbar 29 (see FIG. 8). As the arms 34 start to pivot upwardly and forwardly, the elongated straight line or linear 'slot 33 urges the rollers 32 forwardly and in the direction of movement of the conveyor 12. This forward movement of the crossbar 29 is communicated by means of the rods 22'; to the pivotally-mounted pusher member 25. The

pusher member 25 thereupon engages the lowermost case element 25 is pivotable to pass under the next bottom case,

in the illustration given, 13b, and the relatively slow return of the pusher element 25 does not interfere with the position of a case on the conveyor 12.

While, in the foregoing specification, a detailed description' of anembodiment of the invention has been set down for purposes of explanation thereof, it will be understood 4 that many variationsin these details may be made by those skilled in the art without departing from the spirit 7 and scope of the invention.

I claim:

1. In a case unstacking mechanism,

(A) a frame,

(B) a conveyor including a pair of continuously-running; spaced-apart, horizontally-extending chains, said frame being positioned astride said conveyor,

(C) a carriage mounted on said framefor vertical reciprocation over said conveyor, said carriage hav ing a pair of opposed pads for gripping the secondfrom-the-bottom of a stack of cases to allow the bottom case to be conducted out of said frame,

(D) means for reciprocating said carriage and means for actuating said pads to lower a stack of cases onto said conveyor and thereafter move said carriage upwardly to grip the sec'ond-fr'om-the-bottom case, and

(B) an improved case ejector, comprising:

(1) a guide positioned between said conveyor chains and rigidly interconnected into said frame,

(2) an elongated slide mounted in said guide for movement parallel to said conveyor and equipped at one end witharms extending transversely to the direction of slide movement, each arm carrying a roller rotatably mounted thereon, said slide at the other end being equipped with a pivotally mounted pusher, means mounting said pusher on said'slide for movement from a vertical position through a vertical arc forward in the direction of chain movement whereby said pusher is adapted to push a case out of said frame but have a case pass thereover in entering said frame, v

a (3) a pair of elongated cam arms pivotally mounted on said frame on opposite sides of said conveyor and aligned with said arm rollers, each slot for the receipt of its associated arm roller whereby pivotal 'movementiof said cam arms moves said arm rollers and slide in the direction of conveyor movement, each cam arm being,

equipped with an angled slofland (4) a pair of carriage rollers rotatably mounted on said carriage adjacent the carriage bottom and aligned with said cam arms, a carriage roller being received in each of said angled slots whereby upward movement of said carriage produces pivotal movement of said cam arms and thereby movement of saidpusher in the direction of conveyor movement. f 2. The structure of claim 1 in which said angled slot is equipped with an enlarged angled portion receiving said carriage roller, whereby said pusher is adapted to move more rapidly in'eje cting case-ejecting position. a

a case than in returning'to 3. In a case unstacking mechanism,

(A) a frame, 1

(B) a conveyor including a pair ofcontinuously-running, spaced-apart, horizontally-extending chains, said frame being positioned astride said conveyor,

(C) a carriage mounted on said frame forvertical reciprocation over said conveyor, said carriage having a pair of opposed padsfor gripping the secondfrom-the-bottom of a stack of cases to allowthe bottom case to be conducted out or" said frame,

(D) means for reciprocating said carriageand means for actuating said pads to lower a'stack of cases onto said conveyor and thereafter move said carriage upwar'dly to grip the second-from-the-bottom case, and (E)--an improved case ejector,- comprising:

(1) a guide positioned between said conveyor,

chains and rigidly interconnected into said frame, a V

(2) an elongated slide mounted in said guide for movement parallelto said conveyor and equipped at one end with arms extending transversely to the direction of slide movement, each arm carrying an actuating roller rotatably mounted thereon, said slide at the other end being equipped with a pivotally' mounted pusher, means mount ng said pusher on said slide'for movement from a vertical position through'a vertical arc forward in the direction of chain movement whereby said pusher is adapted to push a case out of said frame but have a case pass thereover in entering said frame, said slide adjacent said other end being equipped with brake rollers, (3) a pair of brake bars on said frame frictionally engaging said brake rollers to retard th movement of said slide, (4) a pair of elongated cam arms pivotally mounted on said frame on opposite sides of said conveyor and aligned, with said actuating rollers,

each of said cam'arms being equipped with a linear slot for the receipt of its associated arm am being equipped with a generally L-shaped' slot, and

(5) a pair'of carriage rollers rotatably mounted on said carriage adjacent the carriage bottom and aligned with said cam arms, a carriage roller being received in each of said Lshaped slots whereby upward movement of said carriage produces pivotal movement of said cam arms and thereby movement of said pusher'in the direction of conveyor movement and only ,when said carriage is gripping the second-fromthe-bottom of a stack of cases. 4. The structure of claim, 3 in which means are provided on said brake bars fixing the same to said frame, said brake bars being resiliently interconnected at the other ends thereof. l i I 5. In a case unstacking (A) a frame, t (B) a conveyor including a pair of continuously-running, spaced-apart, horizontally-extending chains, said frame being positioned astride said conveyor, (C) a carriage mounted on said frame for vertical mechanism,

reciprocation'over said conveyor, said carriage having a pair of opposed pads for gripping thefsecond from the bottom of a stack of cases toallow the A bottom case to be conducted out of said frame, (1)) means for reciprocating said carriage and means foriactua'ting said pads to lower a stack of cases onto I said conveyor and thereafter move said carriage upwardly to grip the second-fron1-the-bottom case, and

(B) an improved case ejector, comprising:

(1) a guide positioned between said conveyor chains and rigidly interconnected into said frame,

(2) an elongated slide mounted in said guide for movement parallel to said conveyor and equipped at one end with a crossbar extending transversely to the direction of slide movement, said crossbar carrying roller means, said slide at the other end being equipped with a pivotally mountj ed pusher, means mounting said pusher on said 3 References Cited in the file of this patent UNITED STATES PATENTS La Bombard ettal. May 8, 1934 Wilder 'Apr 17, 1953 Hageline Aug. 8, 1961 Boller Jan; 22, 1963' V 

3. IN A CASE UNSTACKING MECHANISM, (A) A FRAME, (B) A CONVEYOR INCLUDING A PAIR OF CONTINUOUSLY-RUNNING, SPACED-APART, HORIZONTALLY-EXTENDING CHAINS, SAID FRAME BEING POSITIONED ASTRIDE SAID CONVEYOR, (C) A CARRIAGE MOUNTED ON SAID FRAME FOR VERTICAL RECIPROCATION OVER SAID CONVEYOR, SAID CARRIAGE HAVING A PAIR OF OPPOSED PADS FOR GRIPPING THE SECONDFROM-THE-BOTTOM OF A STACK OF CASES OF ALLOW THE BOTTOM CASE TO BE CONDUCTED OUT OF SAID FRAME, (D) MEANS FOR RECIPROCATING SAID CARRIAGE AND MEANS FOR ACTUATING SAID PADS TO LOWER A STACK OF CASES ONTO SAID CONVEYOR AND THEREAFTER MOVE SAID CARRIAGE UPWARDLY TO GRIP THE SECOND-FROM-THE-BOTTOM CASE, AND (E) AN IMPROVED CASE EJECTOR, COMPRISING: (1) A GUIDE POSITIONED BETWEEN SAID CONVEYOR CHAINS AND RIGIDLY INTERCONNECTED INTO SAID FRAME, (2) AN ELONGATED SLIDE MOUNTED IN SAID GUIDE FOR MOVEMENT PARALLEL TO SAID CONVEYOR AND EQUIPPED AT ONE END WITH ARMS EXTENDING TRANSVERSELY TO THE DIRECTION OF SLIDE MOVEMENT, EACH ARM CARRYING AN ACTUATING ROLLER ROTATABLY MOUNTED THEREON, SAID SLIDE AT THE OTHER END BEING EQUIPPED WITH A PIVOTALLY MOUNTED PUSHER, MEANS MOUNTING SAID PUSHER ON SAID SLIDE FOR MOVEMENT FROM A VERTICAL POSITION THROUGH A VERTICAL ARC FORWARD IN THE DIRECTION OF CHAIN MOVEMENT WHEREBY SAID PUSHER IS ADAPTED TO PUSH A CASE OUT OF SAID FRAME BUT HAVE A CASE PASS THEREOVER IN ENTERING SAID FRAME, SAID SLIDE ADJACENT SAID OTHER END BEING EQUIPPED WITH BRAKE ROLLERS, (3) A PAIR OF BRAKE BARS ON SAID FRAME FRICTIONALLY ENGAGING SAID BRAKE ROLLERS TO RETARD THE MOVEMENT OF SAID SLIDE, (4) A PAIR OF ELONGATED CAM ARMS PIVOTALLY MOUNTED ON SAID FRAME ON OPPOSITE SIDES OF SAID CONVEYOR AND ALIGNED WITH SAID ACTUATING ROLLERS, EACH OF SAID CAM ARMS BEING EQUIPPED WITH A ROLLER WHEREBY PIVOTAL MOVEMENT OF SAID CAM ROLLER WHEREBY PIVOTAL MOVEMENT OF SAID CAM ARMS MOVES SAID ACTUATING ROLLERS AND SLIDE IN THE DIRECTION OF CONVEYOR MOVEMENT, EACH CAM ARM BEING EQUIPPED WITH A GENERALLY L-SHAPED SLOT, AND (5) A PAIR OF CARRIAGE ROLLERS ROTATABLY MOUNTED ON SAID CARRIAGE ADJACENT THE CARRIAGE BOTTOM AND ALIGNED WITH SAID CAM ARMS, A CARRIAGE ROLLER BEING RECEIVED IN EACH OF SAID L-SHAPED SLOTS WHEREBY UPWARD MOVEMENT OF SAID CARRIAGE PRODUCES PIVOTAL MOVEMENT OF SAID CARARMS AND THEREBY MOVEMENT OF SAID PUSHER IN THE DIRECTION OF CONVEYOR MOVEMENT AND ONLY WHEN SAID CARRIAGE IS GRIPPING THE SECOND-FROMTHE-BOTTOM OF A STACK OF CASES. 